Non-Payment of Financial Settlement

I divorced in 2017 (in Scoltand) & was due payment of my Financial Settlement by January 2018, with an 8%pa penalty if Ex did not pay up. Needless to say he didn't & working & living abroad methinks he never had any intention. Being naive at the time, I believed that a legal document/agreement once signed would be honoured & I also had a solicitor who couldn't cope with my Ex's shenannigans. I have spent a considerable amount of time & money over the years with solicitors only to get nowhere. As he is abroad, tho' a British national, there seems to be little that I can do to make him pay up. He is now in Italy, as far as I know, but taking him to court there would be well nigh impossible. I don't mind so much for myself but I have two children & it is their financial security that I am fighting for.
I had to have Legal Aid whilst divorcing him, whilst he went through two solicitors & an Edinburgh Advocate plus a Financial Advisor in an attempt to come out on top. The system is so unfair to those in the divorce who are left in the lurch so to speak.
Any advice welcome.

I'm surprised Italy is that hard to get enforcement. What is the nature of the payment, a lump sum?

It was a lump sum which my Ex was meant to pay by Nov 2017 but was given until Jan 2018 in order to realise the sum. A penalty of 8% per annum on the lump sum if not paid.
I was advised that it would cost £11,000 just to raise the initial case in an Italian court. Not a sum I could afford, I'm afraid.

Unfortunately that is what you would need to do to enforce settlement. There is no other way of doing it unless he has any assets in the UK.